Unilever (Tianjin) Food Factory
Core Solution for Long-Distance, High-Elevation Positive Pressure Pneumatic Conveying System
Customer Background: As a world-leading food production base, the Unilever (Tianjin) plant maintains extremely strict requirements for automation and hygiene standards in its seasoning batching workshop. Within the production line, material conveying efficiency and cross-contamination control are critical factors in ensuring product quality.
1. Technical Challenges & Operating Conditions
The project requires the stable and efficient transport of main powder raw materials to subsequent production processes following iron removal and screening. The core technical difficulties include:
Long-Distance & High-Lift Conveying: A conveying path of 120 meters with a vertical lift of 18 meters poses a significant challenge to pressure maintenance within the pneumatic system.
High Capacity Requirement: The system must maintain a stable conveying capacity of 6 T/H. Any feeding pulsation could negatively impact the batching accuracy of the downstream mixer.
Strict Hygiene Standards: Given the food-grade processing environment, the equipment must meet exceptionally high anti-contamination and easy-to-clean standards.
2. Doebritz Solution
Doebritz customized high-precision Rotary Valves for this project to serve as the core “airlock” and feeding device for the positive pressure pneumatic conveying system:
Superior Airlock Sealing: For the 120m long-distance conveyance, Doebritz rotary valves utilize extremely precise rotor-to-housing clearance control to significantly reduce air leakage, ensuring pressure stability throughout the long-range system.
Food-Grade Materials & Craftsmanship: The interior of the valve body features high-precision polishing and is constructed from 316L stainless steel (compliant with food safety standards). This completely eliminates material stagnation and prevents bacterial growth or material spoilage.
Stable Feeding Design: The optimized rotor blade design ensures uniform, pulse-free material output at a high flow rate of 6 T/H, providing a foundation for precise mixing in the downstream liquid mixer.
3. Project Process Flow
Automated Batching: Raw materials are accurately proportioned according to the formula.
Pre-treatment: Impurities are removed via iron removers and vibrating screens.
Core Feeding (Doebritz Rotary Valve): Materials enter the rotary valve and are smoothly fed into the conveying pipeline while maintaining system pressure.
Positive Pressure Conveying: Materials traverse 120 meters horizontally and 18 meters vertically.
Terminal Receiving: Materials enter the 18m-high receiving tank and finally flow into the liquid mixer.
4. Customer Value & Proof of Strength
By implementing Doebritz’s core rotary valve technology, the Unilever Tianjin plant achieved:
Zero Conveying Blockage: Resolved material accumulation issues common in long-distance conveying, improving system stability by 30%.
Reduced Maintenance Costs: The high durability of Doebritz equipment significantly extends maintenance cycles, ensuring 24/7 continuous production.
Industry Benchmark: The successful implementation of this case demonstrates Doebritz’s industry-leading engineering support and manufacturing capabilities for food-grade pneumatic conveying involving extra-long distances, high capacity, and rigorous hygiene requirements.